Such a direct current discharge lamp may already be taken as known from the prior art and comprises an anode and a cathode that are arranged opposite one another at a predetermined distance inside a discharge vessel (14) filled with a filling gas. In order to produce light, an electric power can be applied to the anode and the cathode, the result being the formation of a gas discharge in the region of an arc.
A disadvantageous circumstance with the known direct current discharge lamps may be seen in the substantial limitation of their useful life by a blackening of the discharge vessel. This blackening results from geometric variations in the surface of the anode facing the cathode in the heated state during operation of the direct current discharge lamp. In this case, local growths occur that lead to a concentration of the attachment of the arc. Very high temperatures that lead to an increased evaporation of the material of the anode can occur at these attachment points. The evaporated anode material is then deposited on the inside of the discharge vessel and leads to said blackening.